1. Field of the Invention
The present invention relates to a wafer processing apparatus and method, a wafer convey robot, a semiconductor substrate fabrication method, and a semiconductor fabrication apparatus and, more particularly, to a wafer processing apparatus and method which process a wafer by dipping the wafer into a processing solution, a wafer convey robot suitable for this processing, and a semiconductor substrate fabrication method and semiconductor fabrication apparatus to which the processing is applied.
2. Description of the Related Art
Wet etching is a typical example of processing performed by dipping a wafer into a solution. One subject of wet etching is to improve the in-plane uniformity. Conventionally, the in-plane uniformity is ensured by supplying fresh etching solution to the reaction surface by circulating the etching solution in a bath.
Another example of the processing performed by dipping a wafer into a solution is wafer cleaning processing. Japanese Patent Laid-Open No. 8-293478 has disclosed a wafer cleaning apparatus which increases the wafer cleaning efficiency by applying ultrasonic waves while dipping part of a wafer into a solution and rotating the wafer.
The wafer cleaning apparatus disclosed in Japanese Patent Laid-Open No. 8-93478 rotates a wafer upon bringing the wafer into contact with a rotating cam, which makes the cam and its accessories generate particles.
In this wafer cleaning apparatus, the strength of standing waves of ultrasonic waves changes at the center and peripheral portion of the wafer. Since the cam obstructs the transmission of ultrasonic waves, the ultrasonic waves cannot be uniformly supplied to the entire surface of the wafer. Accordingly, the wafer cannot be uniformly processed.
In the wafer cleaning apparatus, ultrasonic waves vibrate the cam and the solution in the bath, and as a result, the wafer also vibrates. The wafer and the cam tend to slip with respect to each other, and the wafer cannot rotate uniformly.
In the wafer cleaning apparatus, when a wafer having an orientation flat is to be processed, the conditions for transmitting the rotating force from the cam to the wafer change at the orientation flat and the remaining portion. For this reason, the wafer -cannot rotate uniformly.
The present invention has been made in consideration of the above problems and has as its object to make wafer processing uniform.
It is another object of the present invention to prevent contamination of a wafer caused by particles.
A wafer processing apparatus according to the present invention is a wafer processing apparatus for processing a wafer by dipping the wafer into a processing solution, characterized by comprising a wafer processing bath, a holding portion for directly or indirectly holding the wafer, and a driving portion for supporting the holding portion from above the processing bath to swing the holding portion within the processing bath.
In the wafer processing apparatus, the driving portion preferably also serves as a convey mechanism for conveying the wafer between the apparatus and another apparatus.
The wafer processing apparatus preferably further comprises ultrasonic generating means for generating ultrasonic waves in the processing bath.
The wafer processing apparatus preferably further comprises a swing support member that comes into contact with a peripheral portion of the wafer in swinging the wafer by the driving portion, thereby supporting swinging by the driving portion.
In the wafer processing apparatus, a portion of the swing support member which may come into contact with the peripheral portion of the wafer is preferably rounded.
In the wafer processing apparatus, a portion of the swing support member which may come into contact with the peripheral portion of the wafer preferably has a groove in a direction substantially parallel to a wafer surface.
In the wafer processing apparatus, the groove preferably has a V shape.
In the wafer processing apparatus, the groove preferably has a full-wave rectifying shape.
In the wafer processing apparatus, the processing bath preferably comprises a circulating mechanism including an overflow bath.
In the wafer processing apparatus, the driving portion preferably swings the holding portion to rotate the wafer when the peripheral portion of the wafer comes into contact with the swing support member.
In the wafer processing apparatus, the ultrasonic generating means preferably comprises an ultrasonic bath, an ultrasonic source, and an adjusting mechanism for adjusting a position of the ultrasonic source in the ultrasonic bath, and ultrasonic waves are preferably transmitted to the processing bath via an ultrasonic transmitting medium placed in the ultrasonic bath.
In the wafer processing apparatus, the driving portion preferably comprises a first driving portion for horizontally driving the holding portion, and a second driving portion for vertically driving the holding portion.
In the wafer processing apparatus, the holding portion preferably holds the wafer substantially perpendicular to a bottom surface of the processing bath, and the driving portion preferably swings the wafer within a plane substantially perpendicular to the bottom surface of the processing bath.
In the wafer processing apparatus, the driving portion preferably swings the holding portion within the processing bath to substantially uniformly process the wafer with a processing solution.
In the wafer processing apparatus, the holding portion can preferably hold a wafer holder capable of storing a plurality of wafers.
In the wafer processing apparatus, at least portions of the processing bath, the holding portion, and the driving portion, which may come into contact with a processing solution, are preferably made of a material selected from the group consisting of quartz and plastic.
In the wafer processing apparatus, at least portions of the processing bath, the holding portion, and the driving portion, which may come into contact with a processing solution, are preferably made of a material selected from the group consisting of a fluorine resin, vinyl chloride, polyethylene, polypropylene, polybutyleneterephthalate (PBT), and polyetheretherketone (PEEK).
A wafer convey apparatus according to the present invention is a wafer convey apparatus for conveying a wafer, characterized by comprising a holding portion for directly or indirectly holding the wafer, and a driving portion for driving the holding portion along a convey path, the driving portion dipping the wafer into a wafer processing bath and swinging the wafer midway along the convey path.
In the wafer convey apparatus, the driving portion preferably comprises a first driving portion for horizontally driving the holding portion, and a second driving portion for vertically driving the holding portion.
In the wafer convey apparatus, the holding portion preferably holds the wafer substantially perpendicular to a bottom surface of the processing bath, and the driving portion preferably swings the wafer within a plane substantially perpendicular to the bottom surface of the processing bath.
In the wafer convey apparatus, the driving portion preferably swings the holding portion within the processing bath to substantially uniformly process the wafer with a processing solution in the processing bath.
In the wafer convey apparatus, the driving portion preferably swings the holding portion within the processing bath to enhance swinging of the wafer when a peripheral portion of the wafer comes into contact with a projection formed in the processing bath.
In the wafer convey apparatus, the driving portion preferably swings the holding portion within the processing bath to rotate the wafer when a peripheral portion of the wafer comes into contact with a projection formed in the processing bath.
In the wafer convey apparatus, the holding portion can preferably hold a wafer holder capable of storing a plurality of wafers.
A semiconductor fabrication apparatus according to the present invention is characterized by comprising the wafer convey apparatus, and one or a plurality of wafer processing apparatuses.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer by dipping the wafer into a processing solution, characterized by comprising dipping a wafer into the processing solution while supporting the wafer from above a wafer processing bath, and swinging the wafer within the processing bath. In the wafer processing method, while the wafer is swung within the processing bath, ultrasonic waves are preferably generated in the processing solution.
In the wafer processing method, when the wafer is swung within the processing bath, a peripheral portion of the wafer is preferably brought into contact with a projection formed in the processing bath to enhance swinging of the wafer.
In the wafer processing method, when the wafer is swung within the processing bath, a peripheral portion of the wafer is preferably brought into contact with a projection formed in the processing bath to rotate the wafer.
In the wafer processing method, the wafer is preferably swung to substantially uniformly process the wafer with the processing solution.
The wafer processing method is suitable for etching the wafer by using an etching solution as the processing solution.
The wafer processing method is suitable for etching a wafer having a porous silicon layer by using an etching solution as the processing solution.
An SOI wafer fabrication method according to the present invention is characterized by comprising fabricating an SOI wafer by using the wafer processing method in a part of fabrication steps.
A wafer processing method according to the present invention is characterized by comprising processing a wafer by using the wafer processing apparatus.
A wafer processing method according to the present invention is characterized by comprising etching a specific layer formed on a wafer by using the wafer processing apparatus.
An SOI wafer fabrication method according to the present invention is characterized by comprising fabricating an SOI wafer by using the wafer processing method in a part of fabrication steps.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer while supplying ultrasonic waves, characterized by comprising completely dipping the wafer into a processing solution, and processing the wafer while changing a strength of ultrasonic waves which act on the wafer.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer while supplying ultrasonic waves, characterized by comprising completely dipping the wafer into a processing solution, and processing the wafer while moving the wafer.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer while supplying ultrasonic waves, characterized by comprising completely dipping the wafer in a processing solution, and processing the wafer while swinging the wafer.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer while supplying ultrasonic waves, characterized by comprising completely dipping the wafer in a processing solution, and processing the wafer while swinging the wafer to cross a plane of vibration of ultrasonic waves.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer while supplying ultrasonic waves, characterized by comprising completely dipping the wafer in a processing solution, supporting the wafer substantially perpendicular to a plane of vibration of ultrasonic waves, and processing the wafer while swinging the wafer to cross the plane of vibration of ultrasonic waves.
A wafer processing method according to the present invention is a wafer processing method of processing a wafer while supplying ultrasonic waves, characterized by comprising completely dipping the wafer in a processing solution, supporting the wafer substantially parallel to a plane of vibration of ultrasonic waves, and processing the wafer while swinging the wafer to cross the plane of vibration of ultrasonic waves.
A semiconductor substrate fabrication method according to the present invention is characterized by comprising the step of forming an unporous layer on a porous layer formed on a surface of a first substrate, the step of adhering a first substrate side of a prospective structure and a second substrate prepared separately to sandwich the unporous layer between the first substrate side and the second substrate, the removal step of removing the first substrate from the adhered structure to expose the porous layer on a second substrate side thereof, and the etching step of etching the porous layer while the second substrate side on which the porous layer is exposed is completely dipped into an etching solution, and ultrasonic waves are supplied, thereby exposing a surface of the second substrate side, the etching step changing a strength of ultrasonic waves which act on the second substrate side.
A semiconductor substrate fabrication method according to the present invention is characterized by comprising the step of forming an unporous layer on a porous layer formed on a surface of a first substrate, the step of adhering a first substrate side of a prospective structure and a second substrate prepared separately to sandwich the unporous layer between the first substrate side of a prospective structure and the second substrate, the removal step of removing the first substrate from the adhered structure to expose the porous layer on a second substrate side thereof, and the etching step of etching the porous layer while the second substrate side on which the porous layer is exposed is completely dipped into an etching solution, and ultrasonic waves are supplied, thereby exposing a surface of the second substrate side, the etching step moving the second substrate side.
A semiconductor substrate fabrication method according to the present invention is characterized by comprising the step of forming an unporous layer on a porous layer formed on a surface of a first substrate, the step of adhering a first substrate side of a prospective structure and a second substrate prepared separately to sandwich the unporous layer between the first substrate side and the second substrate, the removal step of removing the first substrate from the adhered structure to expose the porous layer on a second substrate side thereof, and the etching step of etching the porous layer while the second substrate side on. which the porous layer is exposed is completely dipped into an etching solution, and ultrasonic waves are supplied, thereby exposing a surface of the second substrate side, the etching step swinging the second substrate side.
A semiconductor substrate fabrication method according to the present invention is characterized by comprising the step of forming an unporous layer on a porous layer formed on a surface of a first substrate, the step of adhering a first substrate side of a prospective structure and a second substrate prepared separately to sandwich the unporous layer between the first substrate side and the second substrate, the removal step of removing the first substrate from the adhered structure to expose the porous layer on a second substrate side thereof, and the etching step of etching the porous layer while the second substrate side on which the porous layer is exposed is completely dipped into an etching solution, and ultrasonic waves are supplied, thereby exposing a surface of the second substrate side, the etching step swinging the second substrate side to cross a plane of vibration of ultrasonic waves.
A semiconductor substrate fabrication method according to the present invention is characterized by comprising the step of forming an unporous layer on a porous layer formed on a surface of a first substrate, the step of adhering a first substrate side of a prospective structure and a second substrate prepared separately to sandwich the unporous layer between the first substrate side and the second substrate, the removal step of removing the first substrate from the adhered structure to expose the porous layer on a second substrate side thereof, and the etching step of etching the porous layer while the second substrate side on which the porous layer is exposed is completely dipped into an etching solution and supported substantially perpendicular to a plane of vibration of ultrasonic waves, and ultrasonic waves are supplied, thereby exposing a surface of the second substrate side, the etching step swinging the second substrate side to cross the plane of vibration of ultrasonic waves.
A semiconductor substrate fabrication method according to the present invention is characterized by comprising the step of forming an unporous layer on a porous layer formed on a surface of a first substrate, the step of adhering a first substrate side of a prospective structure and a second substrate prepared separately to sandwich the unporous layer between the first substrate side and the second substrate, the removal step of removing the first substrate from the adhered structure to expose the porous layer on a second substrate side thereof, and the etching step of etching the porous layer while the second substrate side on which the porous layer is exposed is completely dipped into an etching solution and supported substantially parallel to a plane of vibration of ultrasonic waves, and ultrasonic waves are supplied, thereby exposing a surface of the second substrate side, the etching step swinging the second substrate side to cross the plane of vibration of ultrasonic waves.
Further objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings.